Airflow control for additive manufacturing

Abstract

A method, apparatus, and program for additive manufacturing. The additive manufacturing device includes a positioning mechanism configured to provide independent movement of at least one build unit in at least two dimensions. The build unit may further include a gasflow device for providing a flow zone along a first direction with relation to the build unit. The build unit may further include a powder delivery mechanism and an irradiation beam directing unit. The irradiation bean unit may follow a first irradiation path, wherein the first irradiation path forms at least a first solidification line and at least a second solidification line formed at an angle other than 0° and 180° with respect to the first solidification line. During the formation of the first solidification line, the build unit may be positioned in a first orientation such that the first direction of the flow zone is substantially perpendicular to the first solidification line. During the formation of the second solidification line, the build unit may be positioned in a second orientation such that the flow zone along the first direction is substantially perpendicular to the second solidification line.

Description

INTRODUCTION[0001]The disclosure relates to an improved method of controlling airflow within an additive manufacturing apparatus.BACKGROUND[0002]Additive manufacturing (AM) techniques may include electron beam freeform fabrication, laser metal deposition (LMD), laser wire metal deposition (LMD-w), gas metal arc-welding, laser engineered net shaping (LENS), laser sintering (SLS), direct metal laser sintering (DMLS), electron beam melting (EBM), powder-fed directed-energy deposition (DED), and three dimensional printing (3DP), as examples. AM processes generally involve the buildup of one or more materials to make a net or near net shape (NNS) object in contrast to subtractive manufacturing methods. Though “additive manufacturing” is an industry standard term (ASTM F2792), AM encompasses various manufacturing and prototyping techniques known under a variety of names, including freeform fabrication, 3D printing, rapid prototyping / tooling, etc. AM techniques are capable of fabricating c...

AI Technical Summary

Benefits of technology

The patent describes an additive manufacturing device that can create objects using a laser and powder technology. The device has a positioning mechanism and a gasflow device that can move in two dimensions. This allows for independent movement of the build unit, which can create lines of solidification in different directions. The device can also have multiple build units that work simultaneously on the same work surface. The technical effects of the patent include improved precision and flexibility in the manufacturing process, as well as faster production times.

Problems solved by technology

Rapid heating and solidification may cause high thermal stress and cause localized non-equilibrium phases throughout the solidified material.

This greatly limits the angular variation of the solidification lines being formed in each layer, thus limiting the ability to control the microstructure of the completed component.

it is necessary to vary the direction of the gas flow 290 which greatly increases the complexity of the AM apparatus.

Further, the variation results in delays which increase build time.

Images